Magnetic control device for yarn guides

ABSTRACT

The invention relates to a control device for activating and deactivating yarn-guides on circular hosiery machines by selectively moving them into and out of operative position, and for similar uses where it is desired to cause a movable portion to selectively assume two different angular positions with respect to a stationary portion. The device allows movement and retention of a magnetically equipped movable member in one or the other of at least two positions responsive to a single current pulse.

nited States Patent Liith 1 Dec. 30, 1975 1 1 MAGNETIC CONTROL DEVICE FOR YARN GUIDES [76] lnventor: Claus-Peter L'Iith, Via delle Cave di {52] US. Cl 66/138; 335/234 [51] Int. Cl. HOIF 7/00 [58] Field of Search ..66/138, 127,125 R, 133;

[56] References Cited UNITED STATES PATENTS 1,211,372 1/1917 Scott 66/138 1,959,016 5 1934 Applegate I 335/234 2,436,354 2/1948 Burke et al. 335/230 3,232,079 2/1966 Levine et al. 66/55 3,274,802 9/1966 Schmidt et a1 66/138 3,418,831 12/1968 Nance 66/138 3,461,690 8/1969 Martinetz et al 66/50 R 3,530,686 9/1970 Martinetz 66/50 R 3,550,398 12/1970 Widdowson 66/50 R FOREIGN PATENTS OR APPLlCATlONS 458,695 11/1949 ltaly 139/122 W 892,792 7/1941 Germany 335/230 Primary Examiner---Wv C. Reynolds Assistant ExaminerAndrew M. Falik [57] ABSTRACT tention of a magnetically equipped movable member in one or the other of at least two positions responsive to a single current pulse.

4 Claims, 5 Drawing Figures US. Patent Dec.30, 1975 Sheet1of-2 3,928,988

MAGNETIC CONTROL DEVICE FOR YARN GUIDES BACKGROUND Circular hosiery knitting machines are equipped with a plurality of yarn guides, each of which is selectively movable into and out of yarn feeding position at selected intervals depending on the programming of the machine to knit a desired pattern. There are conventionally several yarn guides at each feed station, the number of yarn guides at each feed station depending upon the intended capability of the knitting machine to vary the patterns and structures to be knit thereon. There has been increased interest in recent years in multifeed knitting machines, that is circular knitting machines having a plurality of yarn feeds spaced circumferentially around the needle cylinder. The conventional needle cylinder on circular hosiery knitting machines is four inches in diameter and consequently the space on the machine is very limited, particularly when as many as twelve feed stations are employed.

Conventionally, each yarn guide is pivotally mounted on the frame of the machine adjacent the cylinder and is movable, usually downwardly, to direct yarn from a source of supply to the knitting needles as they move past the yarn feed station. A separate yarn guide is providedfor each type of yarn to be used at a given feed station and the two-directional movement of each yarn guide from an upward inactive position to a lower active position is controlled through mechanical linkage by a pattern drum, or in some cases by an electronic control device. The mechanical linkage is often cumbersome, occupying valuable space.

OBJECTS OF THE INVENTION It is, therefore, an object of this invention to provide an electrically operable control device usable in combination with the yarn guides on a circular knitting machine and thereby eliminating the mechanical linkage which has heretofore controlled movement of the yarn guides into and out of operative position.

It is another object of the invention to provide a control apparatus of the type described wherein a magnet is employed in combination with suitably arranged electric coils to actuate a movable member and to retain said movable member in a desired position.

Another object of the invention is to provide said magnet and electrical coils on and in close proximity to the yarn guide and to connect the electric coils to a source of electrical energy with wiring which occupies a minimum of space.

It is a more specific object of the invention to provide a control device including a stationary portion comprising two opposed and symmetric magnetic circuit fixed components, designed to cooperate alternately with a third magnetic circuit component mounted or formed on a movable portion and arranged to establish the closure of a magnetic circuit on the one or on the other of the fixed components according to the position assumed by the movable portion. Means are provided to establish a constant magnetic bias in said magnetic circuit in order to stabilize the position of the movable portion against one or the other of said fixed components of the magnetic circuit, namely, by magnetic attraction. In practice, a permanent magnet serves to generate the constant magnetic bias but the use of a constantly energized electromagnet is not excluded. Solenoid means are so arranged that, when energized, the polarity of 'a magnetic component is reversed to create a magnetic repulsion effect between one of said fixed components and the movable component which is magnetically lodged against said fixed component and thus to repel the movable component away from said one fixed component.

According to a possible embodiment, the two fixed and symmetric components of the magnetic circuit include respective windings, each of which is designed to generate when energized by current a magnetic field of repulsion of the movable component having a constant magnetic polarization or bias.

According to a first alternative, the means to generate a constant magnetic bias may be borne by the movable component. According to an additional alternative, the means to generate a constant magnetic bias may be borne by a fixed element, which forms one or more pairs of symmetric branches forming the fixed components, the movable component being pivotally linked to said element.

In the case of several yarn-guides placed side by side and coaxially pivotally linked, the yarn guides may be provided with a permanent magnet (or the like) arranged alternatively on one side and on the other side of the common linkage, to cooperate with corresponding pairs of fixed components. I

The invention will be better understood and othe objects will appear to those skilled in the art from the following detailed description and the-accompanying drawing, which illustrates embodiments not restricting the invention.

DRAWINGS FIG. 1 is a schematic elevation of the invention wherein a yarn guide is the movable component arranged between the two fixed magnetic circuit components and wherein the fixed components are between the tip of the yarn guide and its pivot point;

FIG. 2 is a view similar to FIG. 1 but showing the pivot point between the fixed components and the tip of the yarn guide;

FIG. 3 perspectively illustrates an arrangement of the permanent magnets with several. yarn-guides placed side by side;

FIG. 4 is a schematic elevation of a fourth embodiment wherein the two fixed components are formed by a single ferromagnetic element;

FIG. 5 is a perspective schematic of a fifth embodiment with two yarn-guides placed side by side.

DETAILED DESCRIPTION Referring to FIGS. 1 and 2, each yarn-guide comprises an elongated yarn finger or rod 1 of non-magnetic material pivotally mounted to the frame of a knitting machine, not shown, by a pivot pin 2 and arranged to reciprocate between the active yarn feeding position shown in solid lines and the raised inactive position shown by the dot-dash lines. The yarn guide includes an eyelet 3 at its operative end through which yarn passes from a source of supply to the knitting needles, not shown. The foregoing arrangement is conventional and is explained in only sufficient detail to provide an environment in which the invention finds utility.

The rod 1 of i the yarn-guide carries a permanent magnet 4 closely adjacent the pivot point 2, the magnet 4 including poles 4N and 48 of opposite polarity. In

3 FIG. 1, the magnet 4 is located between pivot point 2 and eyelet 3, while in the embodiment of FIG. 2 the magnet is arranged between the pivot point 2 and the end of the rod opposite the eyelet 3.

Fixed magnetic components 5 and 6 form U-shaped stops of ferromagnetic material, and-also include coil cores 7 and 8 which form drive solenoids, receptive of electrical energization and de-energization, or of energizations alternatively in two directions to reverse the polarity at the ends of the U-stops.

The operational principle is essentially based on the mutual attraction property of magnetic poles. having opposite polarity and on the mutual repulsion property of magnetic poles having the same polarity. When one of the poles of the permanent magnet 4 contacts one of the two ferromagnetic stops, for instance that shown at 6, in FIG. 2 and the winding8 is de-energized, the rod 1 of the yarn-guide is magnetically engaged in that position without any need of any holding current, as the' magnet induces on the stop 6 magnetic poles of opposite polarity, or in other words, the permanent magnet 4 remains attracted against the iron of the stop 6.

In order to change the position of the yarn-guide, a suitable electric current is sent into the solenoid 8 in the direction wherein the polarity of the stops 6 extending from the ferromagnetic core within coil 8 is changed to the same as that of the poles 4N and 4S of permanent magnet 4, thereby repelling rod 1 and moving it away from stop 6 and toward stop 5 to the inactive position of the yarn guide.

In order to increase the movement of rod 1 toward stop-5 caused by the aforesaid energization of the coil 8, coil 7 can be energized in such a manner as to charge its poles 5 with the opposite polarity of that present in the poles 4N and 4S of permanent magnet 4. In other words, the two electromagnets 6,8 and 5,7 may be simultaneously energized, in such a manner as to respectively and simultaneously repel and attract the permanent magnet 4.

In any case, rod 1 ismoved from the position shown in FIGS. 1 and 2 to the opposite'position shown by the dot-dash lines wherein the magnetic 4 is retained against the unit 5,7. I

By energizing the solenoid 5,7 in such a manner as to obtain the repulsion of the magnet 4 (and preferably by simultaneously energizing the magnet 6,8 to exert an attraction on the same magnet 4), the rod 1 is returned to its original position agains stops 6.

In FIG. 3 a multiple yarn-guides arrangement is shown, with rods 1A, 1B, 1C and 1D pivoted on a common axis 2X. To conserve space, the associated permanent magnets 4A, 4B, 4C, 4D are alternately arranged on opposite sides of the pivot point of their respective rods in the positions of FIGS. 1 and 2, respectively. Their associated electromagnets are correspondingly arranged, there being shown in FIG. 3 only those denoted by 5A, 6A of the yarn-guide rod 1A, 5B and 6B of the rod 18, the one 6C of the rod 1c, and the one 50 of the rod 1D, the other electromagnets being omitted from FIG. 3 for purposes of clarity. With the alterate arrangement of the magnetic controls on opposite sides of the pivot point 2X, the rods of the yarnguides may be closely spaced together and the assembly of multiple yarn-guides desirably compact.

In the embodiment of FIG. 4, a permanent magnet 11 is pivotally connected to a keeper 12 made up of ferromagnetic material and polarized by the magnet 11. Keeper 12 supports the finger or rod of guide 14 and its eyelet 14A. A ferromagnetic element 15 bearing two arms 15A, 15B of the same material is polarized by the magnet 11. The arms 15A, 15B serve as cores for two drive solenoid coils 16A and 16B wound on said arms 15A and 15B.

The operational principle is essentially based on the mutual attraction property ofmagnetic poles having an opposite polarity and of repulsion of magnetic poles having the same polarity andon the possibility of neutralizing a first magnetic field with a field generated with an opposite direction by means of a winding on the same ring on which said first magnetic field is induced.

When the keeper 12 contacts one of the two arms of the assembly 15, for instance, that denoted by 15B, as shownin FIG. 4 and the solenoid 16B is de-energized, there is an attraction force between the keeper l2 and the arm 158 because they are of opposite polarity.

In order to change the position of the keeper 12, a suitable electric current is sent through the solenoid 16B in such a direction as to create on the arm 158 the same polarity'and at least of the same intensity as the polarity present in the keeper. In this way, a repulsion force is created between the arm 15B and the keeper 12, causing keeper 12 to pivot upwardly in FIG. 4 toward arm 15A. Simultaneously, in order to increase the attraction force. between the arm 15A and the keeper l2, a suitable electric current may be sent into the solenoid 16A in such a direction as to reinforce the polarity in arm 15A which is opposite the polarity of the keeper, and thereby increasing the control action on the keeper and thus on the yarn-guide, to change the position.

FIG. 5 shows an arrangement of two yarn-guides, with single permanent magnet 21 which induces a polarity on two distinct keepers 22A, 22B coaxially linked by pivot pin 23 and bearing respectively yarn-guide rods 24A, 24B. The opposite polarity is'induced by the magnet 21 to an element 25 which forms two pairs of arms A, 225A, and 1258, 225B designed to cooperate with the two keepers 22A and 22B, respectively. windings 126 and 226 on said arms of the element 25, energized for each pair of arms as alreadydescribed, allows independent control of the two yarn-guides according to a desired program. g

The invention is capable-of being varied in form and. arrangement without departing from the concept of the invention. For instance, instead of'a permanent magnet one may use a constantly energized electromagnet. Also, one may replace the describedv electromagnets with respective permanent magnets (or constant currentelectromagnets), and replace the permanent magnet described as cooperating with a pair ofelectromagnets, with an electromagnet designed to be run by direct current in reversed directions to obtain the desired switching by magnetic repulsion and attraction.

I claim:

1. In a circular knitting machine having a needle cylinder and a plurality of yarn guides arranged about said cylinder and selectively movable into and out of operating position, the combination of a magnetic control device operatively connected withsaid yarn guides and responsive to electrical'energization to selectively actuate said yarn guides, said magnetic control device comprising a movable component and two stationary components, characterized in that it includes: on each said stationary component, two opposite and symmetric magnetic circuit components designed to alternately cooperate with a magnetic circuit formed on the movable component in such a manner as to establish the closure of a magnetic circuit on one of the stationary components according to the position assumed by the movable component; means to establish a constant magnetic polarization in said magnetic circuit on the movable component in order to stablize the position of said movable component against one of the stationary components of the magnetic circuit by effect of magnetic attraction, and solenoid means arranged to reverse the polarity to create a magnetic repulson effect between one of said stationary components and the movable component which is located against said stationary component.

2. The combination of claim 1 characterized in that it includes a permanent magnet to generate the constant polarization.

3. The combination of claim 2 characterized in that the two fixed and symmetric components of the mag- 6 netic circuit include respectively windings, which when energized selectively generate magnetic fields of the same and opposite polarity as that of the movable component.

4. In a circular knitting machine having a needle cylinder and a plurality of yarn guides arranged about said cylinder and selectively movable into and out of operative positions, the combination of magnetic control means operatively connected with said yarn guides and responsive to electrical energization to selectively actuate said yarn guides, several of said yarn guides being placed side by side and coaxially linked, and wherein magnets are arranged alternatly on one side and on the other side of said coaxial linkage to cooperate with corresponding pairs of stationary magnetic components.

UNITED STATES PATENT AND TRADEMARK OFFICE vCERTIFICATE OF CORRECTION PATENT NO. 3,928,988

DATED Dec. 30, 1975 rrrvrsNroRtsa Claus-Peter Ltith It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the title page, first column, after "Appl. No.

387,517" insert -Foreign Application Priority Data Aug. 12, 1972 Italy .9639/72- Signed and lyealcd this Twenty-seventh Day of July 1976 [SEAL] A ttes t:

RUTH C. MASON V C. MARSHALL DANN Arresting Officer Commissioner uflarenrs and Trademarks UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIUN PATENT NO. 2 3,928,988

DATED Dec. 30, 1975 lN\/ ENTOR(S Claus-PetervLuth It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the title page, first column, after "Appl. No.

387,517" insert -Foreign Application Priority Data Aug. 12, 1972 Italy .9639/72 Signed and Sealed this Twenty-seventh Day of July 1976 [SEAL] A ttes r:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner nfPalenls and Trademarks 

1. In a circular knitting machine having a needle cylinder and a plurality of yarn guides arranged about said cylinder and selectively movable into and out of operating position, the combination of a magnetic control device operatively connected with said yarn guides and responsive to electrical energization to selectively actuate said yarn guides, said magnetic control device comprising a movable component and two stationary components, characterized in that it includes: on each said stationary component, two opposite and symmetric magnetic circuit components designed to alternately cooperate with a magnetic circuit formed on the movable component in such a manner as to establish the closure of a magnetic circuit on one of the stationary components according to the position assumed by the movable component; means to establish a constant magnetic polarization in said magnetic circuit on the movable component in order to stablize the position of said movable component against one of the stationary components of the magnetic circuit by effect of magnetic attraction, and solenoid means arranged to reverse the polarity to create a magnetic repulson effect between one of said stationary components and the movable component which is located against said stationary component.
 2. The combination of claim 1 characterized in that it includes a permanent magnet to generate the constant polarization.
 3. The combination of claim 2 characterized in that the two fixed and symmetric components of the magnetic circuit include respectively windings, which when energized selectively generate magnetic fields of the same and opposite polarity as that of the movable component.
 4. In a circular knitting machine having a needle cylinder and a plurality of yarn guides arranged about said cylinder and selectively movable into and out of operative positions, the combinatiOn of magnetic control means operatively connected with said yarn guides and responsive to electrical energization to selectively actuate said yarn guides, several of said yarn guides being placed side by side and coaxially linked, and wherein magnets are arranged alternatly on one side and on the other side of said coaxial linkage to cooperate with corresponding pairs of stationary magnetic components. 